Reclaiming used lubricating oils



Patented Jan. 22, 194

UNlTE D STATES PATENT OFFICE RECLAIMING USED LUBRICATING John M. Musselman, South Euclid, Ohio, assignor to The Standard Oil Company, Cleveland. Ohio, a corporation of Ohio No Drawing.

. Application October 29, 1942, Serial No. 463,800

16 Claims. (01. 252- 32.?)

Used lubricating oils ordinarily have to be discarded on account of the degradation products contained and change in oil body, notwithstanding the fact that a large part of the oil is yet capable of giving service, Extensive eflorts have been made to reclaim such oils. Among procedures which have been followed are treatment with sulphuric acid, treatment with alkali, treatment with clay, application of selective solvents or rather anti-solvents to precipitate out asphaltic and resinous materials etc. These procedures while affording products which have considerable utility, have been generally unable to turn out a product approaching the standard of the original oil,'and reclaimed oils in general have been regarded as inferior and suitable only for restricted use. In accordance with thepresent invention, oilsmay be reclaimed such as to be capable of usage'like new, and in fact the products may be superior to many oils in their original state. The process moreover is not complicated, and it is conveniently carried out. Other objects and advantages will appear from the following description.

To the accomplishment of the foregoing and related ends, the invention, then, comprisesthe features hereinafter fully described, and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative however, of but a few of the various ways in which the principle of the invention may be employed.

' Used lubricating oil, as for instance from internal combustion engine crankcases, in accordance with the invention, is subjected to treatment with a phosphorus sulphide, as for example pentasulphide, sesquisulphide, etc. The amount of the treating agent need not be gauged exactly to what will be actually used up, although it is desirable to have an approximation of the amount, and it is helpful to know the acid number 01' the amount of oxidation in the oil to be treated, and the wasting of an appreciable surplus of the treating agent may e avoided. Usually for instance, about to 30 parts by weight of the phosphorus sulphide is applied per hundred parts by weight of the oil. On heating the mixture, a reaction occurs with the oxidized components, around temperatures in the neighborhood of 225 F, If the temperature is raisedto a considerably higher level, however as around at least 275 F., or desirably around 300 F., a second type of reaction occurs, and compounds formed between the phosphorus sulphide and the oxidation derivatives in the nature of additive products are, in the second and higher temperature type of reaction changed fundamentally, such that phosphorus is sludged out.

Products formed by the first type of reaction or relatively low temperature treatment are fair products, and oils so reclaimed are of fair grade. However, by treating, or at least finishing the treatment with the higher range temperature operation for the second type of reaction, the products are much superior, and are superior to many new oils. The precipitated matters which form during the treatment are separated, and while in simple cases this may be accomplished by suitable settling, it is desirable more generally to centrifuge or filter. For the best grade of products also, the oil maybe distilled to specification prior to the phosphorus sulphide reaction.

As a further refinement, and yielding products which are even superior to the foregoing, the oil with the phosphorus sulphide treated oil takes place from room temperatures up to around the boiling point of water. While organic bases, as indicated, may be employed, I generally prefer inorganic bases, and these may be ammonia, oxides or hydroxides of metals. Products from reaction with available bases from the first three groups of the periodic system, as the alkalies and alkaline earth compounds, aluminum, etc., have excellent characteristics of tendencies to keep piston surfaces clean where such oils are used in internal combustion engines, and the reaction products of available compounds of the last five groups of the periodic system, or rather the compounds of elements having molecular weight in excess of around 50, are particularly stable in high temperature engine usage, instances being chromium, arsenic, antimony, barium, manganese, etc. In some cases, two or more bases may be applied.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the feasaid used oil-phosphorus pentasulflde reaction with a metal basic compound.

9. A process of reclaiming mineral oils which I have been used tor the lubrication of an internal 2, A process of reclaiming mineral oils which have been used for the lubrication of an internal combustion engine and which contain'degradation products, which process comprises heating said used oil with phosphorus pentasulflde as a principal reactant with said used oil to a temperature to eflect a reaction therebetween to improve the lubricating characteristics of the oil, and separating precipitated matter.

3. A process of reclaiming mineralolls which have been used for the lubrication of an internal combustion engine, which comprises heating the,

used oil containing degradation products with a phosphorus sulphide as the principal reactant with said used oil to at least 225 F., and separat: ing precipitated matter.

4.1K process 01- reclaiming mineral oils which have been used for the lubrication of an internal combustion engine, which comprises heating the used oil containing degradation products with phosphorus pentasulphide as the principal reactant with said used oil to at least 225 F., and separating precipitated matter.

5. A process of reclaiming mineral oilswhich have been used for the lubrication of an internal combustion engine, which comprises heating the used 011 containing degradation products with a phosphorus sulphide as the principal reactant with said used oil at around 300 F., and separating precipitated matter.

6. A process of reclaiming mineral oils which have been used for the lubrication of an internal combustion engine, which comprises heating the used oil containing degradation products with phosphorus pentasulphide as the principal reactant with said used oil at around 300 F., and separatingprecipitated matter.

. 7. A process of reclaiming mineral oils which have been used for -the lubrication of an internal combustion engine and which contain degradation products, which process comprises heating said used oil with a phosphorus sulfide as 'a principal reactant with said used oil to a temperature toeflect a reaction therebetween to improve the lubricating characteristics of the oil, and reacting said used oil-phosphorus sulfide reaction product with a base.

8. A process 01' reclaiming mineral oils which have been used for the lubrication of an internal combustion engine andwhichcontain degradacombustion engine, which comprises. heating the used oil containing degradation products with a phosphorus sulphide as the principal reactant with said used oil to at least 225 F-, and finally reacting said used oil-phosphorus sulphide reaction product with a base.

10. A process or reclaiming mineral oils which have been used for the lubrication oi an internal combustion engine, which comprises heating the used oil containing degradation products with phosphorus pentasulphide as the principal reactant with said used oil to at least 225 F., and finally reacting used oil-phosphorus pentasulphide reaction product with a base. i

.11. A process of reclaiming mineral oils which have been used for the lubrication oi an internal combustion engine, which comprises heating the used oit containing degradation products with a phosphorus sulphide as the principal reactant with said used oil at around300 F., and finally reacting said used oil-phosphorus sulphide reaction product with a base.

12. A process of reclaiming mineral oils which have been used for the lubrication of an internal combustion engine, which comprises heating the used oil containing degradation products with phosphorus pentasulphide as the principal reactant with said used oil at around 300 F" and finally reacting used oil-phosphorus pentasulphide reaction product with a base.

13; A process of reclaiming mineral oils which have been 'used for, the lubrication of an internal combustion engine, which comprises heating the used 011 containing degradation products with a phosphorus sulphide as the principal reactant with said used oil at around-300 0., and finally reacting said used oil-phosphorus sulphide reaction product with a plurality of inorganic bases.

14. A process of reclaiming mineral oils which have been used for the lubrication of an internal combustion engine, which comprises heating the used oil, containing degradation products with phosphorus pentasulphide as the principal react ant with said used oil at around 300 .F'., and finally reacting used oil-phosphorus pentasluphide reaction product with a plurality of inorganic bases.

15. A process of reclaiming mineral oils which have been used for the lubrication of an internal combustion engine, which comprises heating the I used oil containing degradation products with a phosphorus sulphide as the principal reactant with said used oil at around 300 R, separatingsludge, and converting said used oil-phosphorus tion products, which comprises heating said used oil with phosphorus pentasulflde as a principal reactant with said used oil to a temperature to 'eflect a reaction therebetween .to improve the lubricating characterictics oi the oil, and reacting.

sulphide reaction product into a metal compound. 16. A process of reclaiming mineral oils which have been used for the lubrication of an internal combustion engine, which comprises heating the used oil containing degradation products with phosphorus pentasulphide as the principal reactant with-said used oil at around 300 F... separating sludge, and converting said used oil-phosphorus pentasulphide reaction product into a metal compound.

' JOHN M. MUSSELMAN.

CERTIFICATE OF CORRECTIQN.

Patent No. 2,595,555. 5 January 22, 19u6.

' JOHN M. NUSSELMAN rtified that error appears in the printed specification It is'hereby ce lows: Page 2,sec-

of the above numbered patent requining correction as fol 0nd column, line #0, claim 15, for "300 C. said Lettens Patent should be read with this correction therein that the same may conform to the record of the case in the Patent OfficeQ Signed and sealed this 16th day of April, A. Do 19M Leslie Frazex (SeQl) First Assistant Commissioner of P6tents.'

" read --5oo F.--; and that the 

